Tom Pledger writes: In both of those cases, the apparent non-integer dimension is accompanied by a particular unit (km, V). So, could they equally well be handled by stripping away the units and exponentiating a dimensionless number? For example: (x / 1V) ^ y I think not. The "Dimension Types" paper really is excellent, and makes the distinction between the necessity of exponents on the dimensions and the exponents on the numbers very clear; I commend it to everyone in this discussion. The two things (a number of "square root volts" and a "number of volts to an exponent" are different things, unless you are simply trying to represent a ground number as an expression! Dave Barton <*> dlb@averstar.com )0( http://www.averstar.com/~dlb